Fade to black during animation
(from @Robert's original question)
I found an elegant way to fade to black.
go to compositing, enable nodes.
add an 'rgb' node and an 'alpha over' node.
plug the render layers node into the TOP image input
plug the rgb into the BOTTOM image input
animate the factor in the Alpha over.
you wont be able to see it without a 'viewer' node, but it renders nice.
and uh.. set the rgb to black, or whatever colour you want to fade from
or use an image
or a movieclip
world is your oyster